Irrigating Solutions Used in the Biomechanical Preparation of Root Canals

Abstract

Introduction: Microorganisms play an important role in the etiology and persistence of endodontic infections. This microbial population should be eliminated during the biomechanical preparation by the mechanical action of the endodontic instruments, the physicochemical and antimicrobial properties of the auxiliary irrigating solutions, and the action of intracanal medications. Objective: This literature review addresses the main endodontic irrigating solutions used in the biomechanical preparation of the root canal system, as well as the use of irrigating solutions. Conclusions: Sodium hypochlorite (NaOCl) still is the endodontic irrigant of choice. The combination of 1% NaOCl with 16% sodium chloride (NaCl) should be used during biomechanical preparation of root canals due to its antimicrobial activity, organic matter solving capacity and low cytotoxicity. Chlorhexidine at 1% and 2% is used when only antimicrobial activity is required, in cases of microorganisms resistant to endodontic treatment and refractory lesions. A 17% disodium ethylenediaminetetraacetic acid (EDTA) should be used as an auxiliary in the biomechanical preparation of root canals, in the treatment of narrow and calcified canals, and for removal of contaminated smear layer. All irrigating solutions presented limitations. There must be a continuous search for the ideal solution endodontic irrigant, which will be reached only with the investigation and development of new substances.